Journal of Dementia and Alzheimer's Disease

Alzheimer’s disease (AD) pathology is marked by the deposition of amyloid-β plaques and hyperphosphorylated tau neurofibrillary tangles. This pathology begins years before the first clinical symptoms emerge and progresses through several stages before clinical diagnosis. AD’s pathology alters the brain’s functional connectivity (FC) patterns and these altered FC patterns may serve as imaging markers to diagnose and assess the progression of AD. In this review, we summarize the recent literature investigating connectome alterations across the AD spectrum, spanning preclinical, prodromal, and clinical stages. We identify specific regions and functional connections that are altered across different stages of AD and discuss their relevance to cognition. We also highlight the potential of connectome-based predictive modeling as an individual-specific method in the quest for early diagnosis of AD. The default mode network (DMN) shows significant changes across stages, and its core hubs consistently exhibit reduced connectivity with the medial temporal lobe in association with disease pathology. From a dynamic FC point of view, the flexibility of different networks, especially DMN, was reduced as a result of AD onset and persisted across the stages. These disruptions were also linked to reduced cognitive performance, particularly in domains such as memory and executive function. By bringing together evidence on both disease-specific and stage-specific alterations in FC, this review aims to identify patterns that are most informative for understanding AD progression and their potential for advancing early diagnosis.

Background: Postoperative delirium (POD) is commonly observed after surgical aortic valve replacement (SAVR) and could have serious consequences. Its prevalence varied among prior published series. With increasing patient age, a worsening of this problem can be expected. Methods: The association between POD and other adverse events, as well as its effect on 30-day mortality, long-term survival, and later dementia development, was investigated in 1500 consecutive patients (1527 operations) undergoing SAVR with a biological prosthesis, with or without concomitant procedures. An observational retrospective file analysis was performed, using chi-square, Student’s t-test, logistic regression, and Kaplan–Meyer analyses. Results: POD was recorded in 183/1527 (12.0%) of the patient files. Its independent predictors were need for reintervention, age over 80 years, male gender, peripheral artery disease, smoking, need for non-elective SAVR, atrial fibrillation, and a prior TIA. POD was associated with all other postoperative adverse events and increased need for resources. Thirty-day mortality was almost four times higher with POD: 35/182 (19.1%) vs. 59/1345 (4.4%), p < 0.001. Five-year survival was significantly reduced in patients with POD: 79.8 ± 1.2% versus 59.5 ± 4.3%, p < 0.001. The mean time to occurrence of dementia was 89 (84–95) months in patients without POD versus 60 (50–71) months in patients with POD. Five-year freedom from dementia was 69.1 ± 2.9% versus 44.4 ± 6.8%, p < 0.001. Conclusions: POD is associated with short-term complication rates, increased need for resources and hospital mortality, a reduced long-term survival rate, and an increased risk of dementia development. The limitations of this investigation include its retrospective and observational nature; in addition, it did not detect preoperative mild cognitive impairment.

Background/Introduction: Alzheimer’s disease (AD) is a progressive neurological disorder and one of the leading causes of death among older adults in the United States. It causes gradual cognitive decline, memory loss, and impaired functioning. Vulnerable populations—especially those living in rural and predominantly Black communities like the Mississippi Delta—are disproportionately affected. Despite high Alzheimer’s disease mortality rates in Mississippi, limited research has analyzed recent trends disaggregated by race, gender, and geography. This study evaluated trends in AD mortality in the Mississippi Delta between 2016 and 2022 to inform equitable public health responses. Methods: This trend study used age-adjusted mortality rates (AAMRs) for adults aged 65 and older to examine Alzheimer’s disease deaths. AAMRs allow for fair comparisons across groups by adjusting for differences in population age structures. Mortality data were obtained from the Mississippi Statistically Automated Health Resource System (MSTAHRS), a statewide health surveillance system managed by the Mississippi State Department of Health. Joinpoint regression analysis was used to identify statistically significant changes in mortality trends over time using Annual Percent Change (APC) and Average Annual Percent Change (AAPC), with 95% confidence intervals (CIs). AAPC denotes an average percentage change in mortality trends over a seven-year period. Joinpoint regression is an appropriate method for detecting points at which linear trends change significantly, especially in chronic disease mortality analysis. Results: From 2016 to 2022, Alzheimer’s disease mortality significantly increased among Black individuals (AAPC = 8.3%, 95% CI [2.6 to 16.0]; p < 0.05) and declined among White individuals (AAPC = −2.9%, 95% CI [−12.3 to 7.6] p < 0.05). Gender-specific analyses showed slight, non-significant increases among both males and females. County-level disparities were evident: counties such as Sharkey experienced increases exceeding 10%, while Humphreys counties showed declines. Racial disparities in AD mortality were more pronounced than gender differences. Conclusions: This study reveals widening racial and geographic disparities in Alzheimer’s disease mortality across the Mississippi Delta. The statistically significant increase among Black seniors highlights structural inequities in early diagnosis, access to culturally appropriate care, and chronic disease management. These findings support the need for targeted public health interventions, such as the expansion of rural memory clinics, culturally competent outreach, and Medicaid-supported long-term care. Strengthening surveillance systems like MSTAHRS is critical to tracking disparities and advancing equity in dementia-related mortality.